Cheapest-VoIP is a useful international calling rate comparison tool that lets you quickly find the cheapest VoIP calling rate for any country. Simply enter the country where you want to call and click on the ‘Find’ button. Next Cheapest-VoIP will compare the call rates across most of VoIP service providers and sort them starting from the cheapest.

beware of any betamax products....why would they operate under different nams and websites? they come with new one with cheaper rates and increase it later only to appear with another name...thats deceitful.

check out:
callingpowerservices.com
webacall.com

I have used then successfully without any regret and they charge per seconds...